#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define USER "USER"
#define MY_ENV "myval"
#define MYPWD "PWD"

int main()
{
  printf("%s:%s\n",MYPWD,getenv(MYPWD));
  return 0;
}


/*
int main()
{
  char *myenv = getenv(MY_ENV);
  if(NULL == myenv)
  {
    printf("%s,not found\n",MY_ENV);
    return 1;
  }
  printf("%s=%s\n",MY_ENV,myenv);
  return 0;
}
*/ 

/*
int main()
{
  char *who = getenv(USER);
  if(strcmp(who,"root")==0)
  {
     printf("user:%s\n",who);
     printf("user:%s\n",who);
     printf("user:%s\n",who);
     printf("user:%s\n",who);
  }
  else
  {
     printf("权限不足！\n");
  }
  // printf("user:%s\n",who);
  return 0;
}*/ 
